Sea-Level Fingerprints Due to Present-Day Water Mass Redistribution in Observed Sea-Level Data

Lorena Moreira,Anny Cazenave,Anne Barnoud,Jianli Chen

doi:10.3390/rs13224667

Abstract

Satellite altimetry over the oceans shows that the rate of sea-level rise is far from uniform, with reported regional rates up to two to three times the global mean rate of rise of ~3.3 mm/year during the altimeter era. The mechanisms causing the regional variations in sea-level trends are dominated by ocean temperature and salinity changes, and other processes such as ocean mass redistribution as well as solid Earth’s deformations and gravitational changes in response to past and ongoing mass redistributions caused by land ice melt and terrestrial water storage changes (respectively known as Glacial Isostatic Adjustment (GIA) and sea-level fingerprints). Here, we attempt to detect the spatial trend patterns of the fingerprints associated with present-day land ice melt and terrestrial water mass changes, using satellite altimetry-based sea-level grids corrected for the steric component. Although the signal-to-noise ratio is still very low, a statistically significant correlation between altimetry-based sea-level and modelled fingerprints is detected in some ocean regions. We also examine spatial trend patterns in observed GRACE ocean mass corrected for atmospheric and oceanic loading and find that some oceanic regions are dominated by the fingerprints of present-day water mass redistribution.

Highlights

IntroductionA number of studies have investigated the closure of the sea-level budget at global and regional scales over the altimetry era [1,2,3,4,5]
With an explained of ~25%land between the plus terrestrial water mass changes. We suggest that this signal should be removed from steric-corrected altimetry and the modelled fingerprints
The goal was to detect the effects of the present-day land ice melt and terrestrial water mass change in the satellite data

Summary

Introduction

A number of studies have investigated the closure of the sea-level budget at global and regional scales over the altimetry era [1,2,3,4,5]. This is generally carried out by comparing the altimetry-based sea-level change with the sum of contributions using observations (e.g., Gravity Recovery and Climate Experiment (GRACE) satellite gravimetry data for estimating mass changes, and Argo-based ocean temperature and salinity data) or model outputs (e.g., for estimating glacier mass balance). Assessing the closure/nonclosure of the sea-level budget has many implications, such as detecting acceleration [2]

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